How do you unlock the Eitr Refinery, and what does it process?

The Eitr Refinery is a late-game crafting station in Valheim that unlocks the ability to process Eitr, a magical resource used for crafting powerful Mistlands-tier items. To unlock the Eitr Refinery, you must first progress through the game and reach the Mistlands biome, which is one of the most challenging areas in Valheim. This biome is filled with dangerous creatures like Seekers, Gjalls, and Dvergr enemies, so preparation is key.\n\nBefore you can craft the Eitr Refinery, you need to gather specific materials. The refinery requires 20 Black Marble, 5 Black Cores, 10 Yggdrasil Wood, and 5 Sap. Black Marble is obtained by mining Petrified Bones in the Mistlands, while Black Cores are found in Infested Mines, which are dungeons scattered throughout the biome. Yggdrasil Wood is harvested from large, glowing trees in the Mistlands, and Sap is collected from Sap Extractors placed on Yggdrasil Roots.\n\nTo craft the Eitr Refinery, you must first build a Black Forge, which is a crafting station exclusive to the Mistlands. The Black Forge requires 10 Fine Wood, 10 Iron, and 5 Black Cores. Once the Black Forge is constructed, you can place the Eitr Refinery in your base. The refinery processes Soft Tissue, a resource dropped by Mistlands creatures like Seekers and Gjalls, into Eitr. Soft Tissue is also found in Infested Mines and can be looted from Dvergr crates.\n\nOne common challenge players face is locating Infested Mines to gather Black Cores. These mines are often hidden in the dense fog of the Mistlands, making them difficult to find. To overcome this, use a Wisp Light, crafted from Wisps obtained by defeating The Queen boss in the Mistlands. The Wisp Light clears the fog around you, making exploration easier. Additionally, bring plenty of healing items, stamina food, and strong weapons like the Mistwalker or Frostner to handle the tough enemies inside the mines.\n\nOnce you have the Eitr Refinery, you can start producing Eitr, which is essential for crafting advanced Mistlands gear and magical items like the Staff of Embers or the Dead Raiser. Eitr is also used to craft Seeker Aspic, a high-tier food that boosts health, stamina, and Eitr regeneration. To maximize efficiency, place multiple Sap Extractors on Yggdrasil Roots and regularly check them for Sap, as it is a key ingredient for many Mistlands recipes.\n\nFor new players, it’s important to note that the Mistlands biome is end-game content. Before venturing into this area, ensure you have fully upgraded Plains-tier gear, such as Padded Armor and a Blackmetal weapon. Experienced Vikings should focus on building a secure base in the Mistlands to store resources and craft items safely. Always be prepared for combat, as the Mistlands is home to some of the toughest enemies in the game.\n\nIn summary, unlocking the Eitr Refinery requires exploration of the Mistlands biome, gathering rare materials like Black Cores and Sap, and constructing a Black Forge. Once built, the refinery processes Soft Tissue into Eitr, a vital resource for crafting powerful Mistlands gear. Use Wisp Lights to navigate the foggy biome, and always be prepared for combat. With careful planning and resource management, the Eitr Refinery will become a cornerstone of your late-game progression in Valheim.